Lipitor is a brand name for the drug atorvastatin, which is used to treat high cholesterol levels. According to Drug Patent Watch [1], the most common side effects of atorvastatin are muscle pain, joint pain, diarrhea, and indigestion. However, these side effects are usually mild and go away on their own.

The NHS [2] also lists similar side effects, including headaches, nausea, and nosebleeds. However, it notes that these side effects are uncommon and affect less than 1 in 100 people who take atorvastatin.

The Mayo Clinic [3] warns that rare but serious side effects of atorvastatin include liver problems, muscle damage, and an increased risk of diabetes. However, it notes that these side effects are extremely rare and affect less than 1 in 10,000 people who take atorvastatin.

Overall, while atorvastatin (Lipitor) may cause some mild side effects, such as muscle pain and indigestion, these side effects are usually temporary and go away on their own. Serious side effects are extremely rare and affect only a small number of people who take the drug. As with any medication, it is important to talk to your doctor about any concerns or questions you may have about taking atorvastatin.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/
[3] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013